The present invention relates to oil and fat compositions used as general-purpose cooking oils. In particular, the present invention relates to oil and fat compositions containing polyglycerol fatty acid esters, having a high suitability for cooking and exhibiting an excellent antifoaming effect while they are used for cooking.
As heat-cooking oils and fats for deep-frying and stir-frying, there have been used soybean oil, rapeseed oil, corn oil, cotton seed oil, rice bran oil, safflower oil, sunflower oil, sesame oil, olive oil, coconut oil, palm oil, lard and modified oils (transesterified oils and hydrogenated oils) prepared from them alone or in the form of a mixture of two or more of them.
In deep-frying in an oil or fat, a vapor is usually formed from a material being fried and, as a result, foams are formed. While the frying is repeated, the oil or fat is deteriorated and the foaming thereof is accelerated by an influence of ingredients eluted from the materials in the course of the deep-frying. When the foaming is serious, the materials are hidden by the foams and they cannot be seen, and the foams overflow from the pan to make the cooking operation dangerous. Accordingly, the amount of the material that can be deep-fried in the oil is limited. Particularly when the material to be deep-fried contains eggs or meats, the oil or fat is rapidly deteriorated. For controlling the foaming of the oil in the course of the deep-frying, a silicone oil has been added to the oil. However, the use of the silicone oil is recently avoided because the effect thereof is limited and the biodegradability thereof is only low.
A mixed oil of coconut oil and soybean oil and a transesterified oil prepared from medium length fatty acid triglycerides and rapeseed oil foam relatively easily to form a large quantity of the foams. The foaming of triglycerides comprising both fatty acids having 6 to 12 carbon atoms and fatty acids having 14 to 22 carbon atoms cannot be controlled even by the addition of the silicone.